SummaryPresentation of the Nephrology Quiz and Questionnaire (NQQ) has become an annual tradition at the meetings of the American Society of Nephrology. It is a very popular session, judged by consistently large attendance. Members of the audience test their knowledge and judgment on a series of case-oriented questions prepared and discussed by experts. They can also compare their answers in real time, using audience response devices, to those of program directors of nephrology training programs in the United States, acquired through an Internet-based questionnaire. The topic presented here is GN. Cases representing this category, along with single best answer questions, were prepared by a panel of experts (Drs. Fervenza, Glassock, and Bleyer). The correct and incorrect answers were then briefly discussed after the audience responses and the results of the questionnaire were displayed. This article recapitulates the session and reproduces its educational value for a larger audience-that of the readers of the Clinical Journal of the American Society of Nephrology. Have fun.Clin J Am Soc Nephrol 8: 1460-1465, 2013. doi: 10.2215/CJN.00440113
GN Case 1A 20-year-old woman was referred for evaluation of persistent hematuria and proteinuria. She had a history of fever and sore throat lasting 1 week that occurred 6 months earlier and were associated with abdominal pain and dark urine. She did not receive any antimicrobial agents. Significant findings on physical examination at that time included a BP of 140/90 mmHg and 2+ edema. Laboratory evaluation showed a serum creatinine value of 1.4 mg/dl, urinalysis with 2+ protein and 3+ blood, and a 24-hour urinary protein excretion of 680 mg. The C3 level was 46 mg/dl (reference range, 75-175 mg/dl) and the C4 level was 23 mg/dl (reference range, 14-40 mg/dl). A throat culture was negative for b-hemolytic streptococci, and an antistreptolysin O titer was 200 IU/ml (upper limit of normal, 200 IU/ml). The serum albumin concentration was 3.6 g/dl.A renal biopsy was performed and showed a pattern of membranoproliferative GN on light microscopy. No crescents were observed. Immunofluorescence microscopy showed bright (3+) mesangial and capillary wall C3 staining. Electron microscopy showed mesangial, intramembranous, and subendothelial deposits, as well as a few subepithelial hump-like deposits. Postinfectious GN and type III membranoproliferative GN were diagnosed. The patient was treated symptomatically, but proteinuria and hematuria persisted. Current evaluation shows a hemoglobin level of 11.8 g/dl, a serum creatinine concentration of 1.3 mg/dl, urinalysis with 3+ blood and 3+ protein, quantitative proteinuria of 2.2 g/24 hours, C3 concentration of 44 mg/dl, and C4 concentration of 22 mg/dl.
Question 1 (see Figure 1 for responses of program directors and attendees)To further evaluate this patient, you would now order:A. Antinuclear antibodies B. Hepatitis B and C serology C. Anti-deoxyribonuclease (DNase) antibody titers D. Serum C1q level E. Antibodies to complement-regulating ...